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Segars KL, Azzari N, Cole M, Kushimi L, Rapaka S, Rich CB, Trinkaus-Randall V. Diverse calcium signaling profiles regulate migratory behavior in avascular wound healing and aberrant signal hierarchy occurs early in diabetes. Am J Physiol Cell Physiol 2024; 327:C1051-C1072. [PMID: 39129489 DOI: 10.1152/ajpcell.00249.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 08/06/2024] [Accepted: 08/06/2024] [Indexed: 08/13/2024]
Abstract
In avascular wound repair, calcium signaling events are the predominant mechanism cells use to transduce information about stressors in the environment into an effective and coordinated migratory response. Live cell imaging and computational analysis of corneal epithelial wound healing revealed that signal initiation and propagation at the wound edge are highly ordered, with groups of cells engaging in cyclical patterns of initiation and propagation. The cells in these groups exhibit a diverse range of signaling behavior, and dominant "conductor cells" drive activity in groups of lower-signaling neighbors. Ex vivo model systems reveal that conductor cells are present in wing cell layers of the corneal epithelium and that signaling propagates both within and between wing and basal layers. There are significant aberrations in conductor phenotype and interlayer propagation in type II diabetic murine models, indicating that signal hierarchy breakdown is an early indicator of disease. In vitro models reveal that signaling profile diversity and conductor cell phenotype is eliminated with P2X7 inhibition and is altered in Pannexin-1 or P2Y2 but not Connexin-43 inhibition. Conductor cells express significantly less P2X7 than their lower-signaling neighbors and exhibit significantly less migratory behavior after injury. Together, our results show that the postinjury calcium signaling cascade exhibits significantly more ordered and hierarchical behavior than previously thought, that proteins previously shown to be essential for regulating motility are also essential for determining signaling phenotype, and that loss of signal hierarchy integrity is an early indicator of disease state. NEW & NOTEWORTHY Calcium signaling in corneal epithelial cells after injury is highly ordered, with groups of cells engaged in cyclical patterns of event initiation and propagation driven by high-signaling cells. Signaling behavior is determined by P2X7, Pannexin-1, and P2Y2 and influences migratory behavior. Signal hierarchy is observed in healthy ex vivo models after injury and becomes aberrant in diabetes. This represents a paradigm shift, as signaling was thought to be random and determined by factors in the environment.
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Affiliation(s)
- Kristen L Segars
- Department of Pharmacology, Physiology, and Biophysics, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Nicholas Azzari
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Malia Cole
- STaRS Program, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Landon Kushimi
- Department of Computer Science, Boston University Center for Computing and Data Sciences, Boston, Massachusetts, United States
| | - Srikar Rapaka
- Department of Medicine, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Celeste B Rich
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
| | - Vickery Trinkaus-Randall
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
- Department of Ophthalmology, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, United States
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Krzemiński P, Misiewicz-Krzemińska I, Grodzik M, Padzińska-Pruszyńska I, Kucharzewska P, Ostrowska A, Sawosz E, Pomorski P. The protective effect of silver nanoparticles' on epithelial cornea cells against ultraviolet is accompanied by changes in calcium homeostasis and a decrease of the P2X7 and P2Y2 receptors. Biomed Pharmacother 2024; 170:116090. [PMID: 38169187 DOI: 10.1016/j.biopha.2023.116090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/18/2023] [Accepted: 12/26/2023] [Indexed: 01/05/2024] Open
Abstract
PURPOSE The aim of the study was to evaluate the effect of silver nanoparticles hydrocolloids (AgNPs) on human corneal epithelial cells. Epithelial cells form the outermost and the most vulnerable to environmental stimuli layer of the cornea in the eye. Mechanical stress, UV radiation, and pathogens such as bacteria, viruses, and parasites challenge the fragile homeostasis of the eye. To help combat stress, infection, and inflammation wide portfolio of interventions is available. One of the oldest treatments is colloidal silver. Silver nanoparticle suspension in water is known for its anti-bacterial anti-viral and antiprotozoal action. However, AgNPs interact also with host cells, and the character of the interplay between corneal cells and silver seeks investigation. METHODS The human epithelial corneal cell line (HCE-2) was cultured in vitro, treated with AgNPs, and subjected to UV. The cell's viability, migration, calcium concentration, and expression/protein level of selected proteins were investigated by appropriate methods including cytotoxicity tests, "wound healing" assay, Fluo8/Fura2 AM staining, qRT-PCR, and western blot. RESULTS Incubation of human corneal cells (HCE-2) with AgNP did not affect cells viability but limited cells migration and resulted in altered calcium homeostasis, decreased the presence of ATP-activated P2X7, P2Y2 receptors, and enhanced the expression of PACAP. Furthermore, AgNPs pretreatment helped restrain some of the deleterious effects of UV irradiation. Interestingly, AgNPs had no impact on the protein level of ACE2, which is important in light of potential SARS-CoV-2 entrance through the cornea. CONCLUSIONS Silver nanoparticles are safe for corneal epithelial cells in vitro.
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Affiliation(s)
- Patryk Krzemiński
- Department of Nanobiotechnology, Insitute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, bldg. 23, 02-786 Warsaw, Poland.
| | - Irena Misiewicz-Krzemińska
- Plasma Cell Neoplasm Laboratory, Department of Experimental Haematology, Institute of Hematology and Blood Transfusion, Chocimska 5, 00-791 Warsaw, Poland
| | - Marta Grodzik
- Department of Nanobiotechnology, Insitute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, bldg. 23, 02-786 Warsaw, Poland
| | - Irena Padzińska-Pruszyńska
- Department of Cancer Biology, Institute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, bldg. 23, 02-786 Warsaw, Poland
| | - Paulina Kucharzewska
- Department of Cancer Biology, Institute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, bldg. 23, 02-786 Warsaw, Poland
| | - Agnieszka Ostrowska
- Department of Nanobiotechnology, Insitute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, bldg. 23, 02-786 Warsaw, Poland
| | - Ewa Sawosz
- Department of Nanobiotechnology, Insitute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, bldg. 23, 02-786 Warsaw, Poland
| | - Paweł Pomorski
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Pasteura 3, 02-093 Warsaw, Poland
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Azzari NA, Segars KL, Rapaka S, Kushimi L, Rich CB, Trinkaus-Randall V. Aberrations in Cell Signaling Quantified in Diabetic Murine Globes after Injury. Cells 2023; 13:26. [PMID: 38201230 PMCID: PMC10778404 DOI: 10.3390/cells13010026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
The corneal epithelium is an avascular structure that has a unique wound healing mechanism, which allows for rapid wound closure without compromising vision. This wound healing mechanism is attenuated in diabetic patients, resulting in poor clinical outcomes and recurrent non-healing erosion. We investigated changes in cellular calcium signaling activity during the wound response in murine diabetic tissue using live cell imaging from both ex vivo and in vitro models. The calcium signaling propagation in diabetic cells was significantly decreased and displayed altered patterns compared to non-diabetic controls. Diabetic cells and tissue display distinct expression of the purinergic receptor, P2X7, which mediates the wound healing response. We speculate that alterations in P2X7 expression, interactions with other proteins, and calcium signaling activity significantly impact the wound healing response. This may explain aberrations in the diabetic wound response.
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Affiliation(s)
- Nicholas A. Azzari
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; (N.A.A.); (C.B.R.)
| | - Kristen L. Segars
- Department of Pharmacology, Physiology and Biophysics, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA;
| | - Srikar Rapaka
- Department of Medicine, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA;
| | - Landon Kushimi
- Department of Computer Science, Center for Computing and Data Sciences, Boston University, 665 Commonwealth Ave, Boston, MA 02115, USA;
| | - Celeste B. Rich
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; (N.A.A.); (C.B.R.)
| | - Vickery Trinkaus-Randall
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; (N.A.A.); (C.B.R.)
- Department of Pharmacology, Physiology and Biophysics, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA;
- Department of Ophthalmology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA
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4
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Lee EEL, O'Malley-Krohn I, Edsinger E, Wu S, Malamy J. Epithelial wound healing in Clytia hemisphaerica provides insights into extracellular ATP signaling mechanisms and P2XR evolution. Sci Rep 2023; 13:18819. [PMID: 37914720 PMCID: PMC10620158 DOI: 10.1038/s41598-023-45424-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/19/2023] [Indexed: 11/03/2023] Open
Abstract
Epithelial wound healing involves the collective responses of many cells, including those at the wound margin (marginal cells) and those that lack direct contact with the wound (submarginal cells). How these responses are induced and coordinated to produce rapid, efficient wound healing remains poorly understood. Extracellular ATP (eATP) is implicated as a signal in epithelial wound healing in vertebrates. However, the role of eATP in wound healing in vivo and the cellular responses to eATP are unclear. Almost nothing is known about eATP signaling in non-bilaterian metazoans (Cnidaria, Ctenophora, Placozoa, and Porifera). Here, we show that eATP promotes closure of epithelial wounds in vivo in the cnidarian Clytia hemisphaerica (Clytia) indicating that eATP signaling is an evolutionarily ancient strategy in wound healing. Furthermore, eATP increases F-actin accumulation at the edges of submarginal cells. In Clytia, this indicates eATP is involved in coordinating cellular responses during wound healing, acting in part by promoting actin remodeling in cells at a distance from the wound. We also present evidence that eATP activates a cation channel in Clytia epithelial cells. This implies that the eATP signal is transduced through a P2X receptor (P2XR). Phylogenetic analyses identified four Clytia P2XR homologs and revealed two deeply divergent major branches in P2XR evolution, necessitating revision of current models. Interestingly, simple organisms such as cellular slime mold appear exclusively on one branch, bilaterians are found exclusively on the other, and many non-bilaterian metazoans, including Clytia, have P2XR sequences from both branches. Together, these results re-draw the P2XR evolutionary tree, provide new insights into the origin of eATP signaling in wound healing, and demonstrate that the cytoskeleton of submarginal cells is a target of eATP signaling.
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Affiliation(s)
- Elizabeth E L Lee
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Isabel O'Malley-Krohn
- Biological Sciences Collegiate Division, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Eric Edsinger
- Whitney Laboratory for Marine Biosciences, University of Florida, 9505 N Ocean Shore Blvd, St. Augustine, FL, 32080, USA
| | - Stephanie Wu
- Biological Sciences Collegiate Division, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA
| | - Jocelyn Malamy
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 929 East 57th Street, Chicago, IL, 60637, USA.
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5
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Wang JN, Fan H, Song JT. Targeting purinergic receptors to attenuate inflammation of dry eye. Purinergic Signal 2023; 19:199-206. [PMID: 35218451 PMCID: PMC9984584 DOI: 10.1007/s11302-022-09851-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/04/2022] [Indexed: 11/28/2022] Open
Abstract
Inflammation is one of the potential factors to cause the damage of ocular surface in dry eye disease (DED). Increasing evidence indicated that purinergic A1, A2A, A3, P2X4, P2X7, P2Y1, P2Y2, and P2Y4 receptors play an important role in the regulation of inflammation in DED: A1 adenosine receptor (A1R) is a systemic pro-inflammatory factor; A2AR is involved in the activation of the MAPK/NF-kB pathway; A3R combined with inhibition of adenylate cyclase and regulation of the mitogen-activated protein kinase (MAPK) pathway leads to regulation of transcription; P2X4 promotes receptor-associated activation of pro-inflammatory cytokines and inflammatory vesicles; P2X7 promotes inflammasome activation and release of pro-inflammatory cytokines IL-1β and IL-18; P2Y receptors affect the phospholipase C(PLC)/IP3/Ca2+ signaling pathway and mucin secretion. These suggested that purinergic receptors would be promising targets to control the inflammation of DED in the future.
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Affiliation(s)
- Jia-Ning Wang
- Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Hua Fan
- Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jian-Tao Song
- Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
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Yu FSX, Lee PSY, Yang L, Gao N, Zhang Y, Ljubimov AV, Yang E, Zhou Q, Xie L. The impact of sensory neuropathy and inflammation on epithelial wound healing in diabetic corneas. Prog Retin Eye Res 2022; 89:101039. [PMID: 34991965 PMCID: PMC9250553 DOI: 10.1016/j.preteyeres.2021.101039] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 12/10/2021] [Accepted: 12/20/2021] [Indexed: 02/08/2023]
Abstract
Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes, with several underlying pathophysiological mechanisms, some of which are still uncertain. The cornea is an avascular tissue and sensitive to hyperglycemia, resulting in several diabetic corneal complications including delayed epithelial wound healing, recurrent erosions, neuropathy, loss of sensitivity, and tear film changes. The manifestation of DPN in the cornea is referred to as diabetic neurotrophic keratopathy (DNK). Recent studies have revealed that disturbed epithelial-neural-immune cell interactions are a major cause of DNK. The epithelium is supplied by a dense network of sensory nerve endings and dendritic cell processes, and it secretes growth/neurotrophic factors and cytokines to nourish these neighboring cells. In turn, sensory nerve endings release neuropeptides to suppress inflammation and promote epithelial wound healing, while resident immune cells provide neurotrophic and growth factors to support neuronal and epithelial cells, respectively. Diabetes greatly perturbs these interdependencies, resulting in suppressed epithelial proliferation, sensory neuropathy, and a decreased density of dendritic cells. Clinically, this results in a markedly delayed wound healing and impaired sensory nerve regeneration in response to insult and injury. Current treatments for DPN and DNK largely focus on managing the severe complications of the disease. Cell-based therapies hold promise for providing more effective treatment for diabetic keratopathy and corneal ulcers.
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Affiliation(s)
- Fu-Shin X Yu
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
| | - Patrick S Y Lee
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Lingling Yang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Nan Gao
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Yangyang Zhang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Alexander V Ljubimov
- Departments of Biomedical Sciences and Neurosurgery, Cedars-Sinai Medical Center, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Ellen Yang
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA
| | - Qingjun Zhou
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Lixin Xie
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China.
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7
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Segars KL, Azzari NA, Gomez S, Machen C, Rich CB, Trinkaus-Randall V. Age Dependent Changes in Corneal Epithelial Cell Signaling. Front Cell Dev Biol 2022; 10:886721. [PMID: 35602595 PMCID: PMC9117764 DOI: 10.3389/fcell.2022.886721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/19/2022] [Indexed: 11/25/2022] Open
Abstract
The cornea is exposed daily to a number of mechanical stresses including shear stress from tear film and blinking. Over time, these stressors can lead to changes in the extracellular matrix that alter corneal stiffness, cell-substrate structures, and the integrity of cell-cell junctions. We hypothesized that changes in tissue stiffness of the cornea with age may alter calcium signaling between cells after injury, and the downstream effects of this signaling on cellular motility and wound healing. Nanoindentation studies revealed that there were significant differences in the stiffness of the corneal epithelium and stroma between corneas of 9- and 27-week mice. These changes corresponded to differences in the timeline of wound healing and in cell signaling. Corneas from 9-week mice were fully healed within 24 h. However, the wounds on corneas from 27-week mice remained incompletely healed. Furthermore, in the 27-week cohort there was no detectable calcium signaling at the wound in either apical or basal corneal epithelial cells. This is in contrast to the young cohort, where there was elevated basal cell activity relative to background levels. Cell culture experiments were performed to assess the roles of P2Y2, P2X7, and pannexin-1 in cellular motility during wound healing. Inhibition of P2Y2, P2X7, or pannexin-1 all significantly reduce wound closure. However, the inhibitors all have different effects on the trajectories of individual migrating cells. Together, these findings suggest that there are several significant differences in the stiffness and signaling that underlie the decreased wound healing efficacy of the cornea in older mice.
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Affiliation(s)
- Kristen L. Segars
- Department of Pharmacology, School of Medicine, Boston University, Boston, MA, United States
| | - Nicholas A. Azzari
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
| | - Stephanie Gomez
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
| | - Cody Machen
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
| | - Celeste B. Rich
- Department of Ophthalmology, School of Medicine, School of Medicine, Boston, MA, United States
| | - Vickery Trinkaus-Randall
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
- Department of Ophthalmology, School of Medicine, School of Medicine, Boston, MA, United States
- *Correspondence: Vickery Trinkaus-Randall,
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Pannexin1: Role as a Sensor to Injury Is Attenuated in Pretype 2 Corneal Diabetic Epithelium. ACTA ACUST UNITED AC 2021; 2021:4793338. [PMID: 34336553 PMCID: PMC8295002 DOI: 10.1155/2021/4793338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 07/07/2021] [Indexed: 11/17/2022]
Abstract
Epithelial wound healing is essential to repair the corneal barrier function after injury and requires coordinated epithelial sheet movement over the wounded region. The presence and role of pannexin1 on multilayered epithelial sheet migration was examined in unwounded and wounded corneal epithelium from C57BL/6J (B6) control and diet-induced obese (DiO) mice, a pretype 2 diabetic model. We hypothesize that pannexin1 is dysregulated, and the interaction of two ion-channel proteins (P2X7 and pannexin1) is altered in pretype 2 diabetic tissue. Pannexin1 was found to be present along cell borders in unwounded tissue, and no significant difference was observed between DiO and B6 control. However, an epithelial debridement induced a striking difference in pannexin1 localization. The B6 control epithelium displayed intense staining near the leading edge, which is the region where calcium mobilization was detected, whereas the staining in the DiO corneal epithelium was diffuse and lacked distinct gradation in intensity back from the leading edge. Cells distal to the wound in the DiO tissue were irregular in shape, and the morphology was similar to that of epithelium inhibited with 10Panx, a pannexin1 inhibitor. Pannexin1 inhibition reduced mobilization of calcium between cells near the leading edge, and MATLAB scripts revealed a reduction in cell-cell communication that was also detected in cultured cells. Proximity ligation was performed to determine if P2X7 and pannexin1 interaction was a necessary component of motility and communication. While there was no significant difference in the interaction in unwounded DiO and B6 control corneal epithelium, there was significantly less interaction in the wounded DiO corneas both near the wound and back from the edge. The results demonstrate that pannexin1 contributes to the healing response, and P2X7 and pannexin1 coordination may be a required component of cell-cell communication and an underlying reason for the lack of pathologic tissue migration.
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9
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Brenet M, Martínez S, Pérez-Nuñez R, Pérez LA, Contreras P, Díaz J, Avalos AM, Schneider P, Quest AFG, Leyton L. Thy-1 (CD90)-Induced Metastatic Cancer Cell Migration and Invasion Are β3 Integrin-Dependent and Involve a Ca 2+/P2X7 Receptor Signaling Axis. Front Cell Dev Biol 2021; 8:592442. [PMID: 33511115 PMCID: PMC7835543 DOI: 10.3389/fcell.2020.592442] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/04/2020] [Indexed: 01/21/2023] Open
Abstract
Cancer cell adhesion to the vascular endothelium is an important step in tumor metastasis. Thy-1 (CD90), a cell adhesion molecule expressed in activated endothelial cells, has been implicated in melanoma metastasis by binding to integrins present in cancer cells. However, the signaling pathway(s) triggered by this Thy-1-Integrin interaction in cancer cells remains to be defined. Our previously reported data indicate that Ca2+-dependent hemichannel opening, as well as the P2X7 receptor, are key players in Thy-1-αVβ3 Integrin-induced migration of reactive astrocytes. Thus, we investigated whether this signaling pathway is activated in MDA-MB-231 breast cancer cells and in B16F10 melanoma cells when stimulated with Thy-1. In both cancer cell types, Thy-1 induced a rapid increase in intracellular Ca2+, ATP release, as well as cell migration and invasion. Connexin and Pannexin inhibitors decreased cell migration, implicating a requirement for hemichannel opening in Thy-1-induced cell migration. In addition, cell migration and invasion were precluded when the P2X7 receptor was pharmacologically blocked. Moreover, the ability of breast cancer and melanoma cells to transmigrate through an activated endothelial monolayer was significantly decreased when the β3 Integrin was silenced in these cancer cells. Importantly, melanoma cells with silenced β3 Integrin were unable to metastasize to the lung in a preclinical mouse model. Thus, our results suggest that the Ca2+/hemichannel/ATP/P2X7 receptor-signaling axis triggered by the Thy-1-αVβ3 Integrin interaction is important for cancer cell migration, invasion and transvasation. These findings open up the possibility of therapeutically targeting the Thy-1-Integrin signaling pathway to prevent metastasis.
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Affiliation(s)
- Marianne Brenet
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Samuel Martínez
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Ramón Pérez-Nuñez
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Leonardo A Pérez
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Pamela Contreras
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Jorge Díaz
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Ana María Avalos
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Pascal Schneider
- Department of Biochemistry, University of Lausanne, Epalinges, Switzerland
| | - Andrew F G Quest
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Lisette Leyton
- Cellular Communication Laboratory, Program of Cellular & Molecular Biology, Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, Universidad de Chile, Santiago, Chile
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Yang HM, Kang SW, Sung J, Kim K, Kleinman H. Purinergic Signaling Involvement in Thymosin β4-mediated Corneal Epithelial Cell Migration. Curr Eye Res 2020; 45:1352-1358. [PMID: 32223337 DOI: 10.1080/02713683.2020.1748891] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Purpose: This study aimed to determine the effect of thymosin beta 4 (Tβ4) on human corneal epithelial cell migration and the downstream signaling pathways. Tβ4 has a role in tissue development, cell migration, inflammation, and wound healing. A previous study showed that Tβ4 directly binds to F0-F1 ATP synthase. Other studies reported the role of extracellular ATP and purinergic receptors in cell migration with several cell types. Despite advancing to the clinical stage for treatment of eye disorders, the effect of Tβ4 on human corneal epithelial cell (HCEC) migration and proliferation and the precise downstream signaling pathway(s) have not been identified. Methods: Various concentrations of Tβ4 were tested in vitro on human corneal epithelial cell proliferation using the CCK-8 Kit and on cell migration using the gap closure migration assay. Additionally, ATP levels at various time points were determined using the ATP Lite One-Step Kit. The Fluo 8 NO Wash Calcium Assay Kit was used to measure the intracellular Ca2+ concentration after treatment with various concentrations of Tβ4. P2X7 inhibitors were tested on ATP signaling and migration. Total- and phospho-ERK1/2 levels were determined in western blot. Results: Tβ4 enhanced HCEC proliferation and migration in a dose- and time-dependent manner. Moreover, these functions were related to increased extracellular ATP levels, intracellular Ca2+ influx, and ERK1/2 phosphorylation. Tβ4-mediated HCEC migration was inhibited by specific P2X7 purinergic receptor antagonists suggesting the role of this receptor in Tβ4-mediated human corneal epithelial cell migration. Conclusions: These results suggest that Tβ4-mediated HCEC proliferation and migration are associated with increased ATP levels, P2X7 R-mediated Ca2+ influx, and the ERK1/2 signaling pathway. This study begins to describe the mechanisms for Tβ4-mediated corneal healing and regeneration.
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Affiliation(s)
- Heung-Mo Yang
- Department of Medicine, Sungkyunkwan University School of Medicine , Gyeonggi, Republic of Korea.,Stem Cell & Regenerative Medicine Institute, Samsung Medical Center , Seoul, Republic of Korea
| | | | - Jihye Sung
- GtreeBNT Co., Ltd ., Seongnam-si, Republic of Korea
| | - Kyeongsoon Kim
- GtreeBNT Co., Ltd ., Seongnam-si, Republic of Korea.,Department of Pharmaceutical Engineering, Inje University , Gimhae-si, Republic of Korea
| | - Hynda Kleinman
- The Laboratory of Cell and Developmental Biology, NIH, NIDCR , Bethesda, Maryland, USA
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11
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Skarratt KK, Gu BJ, Lovelace MD, Milligan CJ, Stokes L, Glover R, Petrou S, Wiley JS, Fuller SJ. A P2RX7 single nucleotide polymorphism haplotype promotes exon 7 and 8 skipping and disrupts receptor function. FASEB J 2020; 34:3884-3901. [PMID: 32003498 DOI: 10.1096/fj.201901198rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/12/2022]
Abstract
P2X7 is an ATP-gated membrane ion channel that is expressed by multiple cell types. Brief exposure to ATP induces the opening of a nonselective cation channel; while repeated or prolonged exposure induces formation of a transmembrane pore. This process may be partially regulated by alternative splicing of full-length P2RX7A pre-mRNA, producing isoforms that delete or retain functional domains. Here, we report cloning and expression of a novel P2RX7 splice variant, P2RX7L, that is, characterized by skipping of exons 7 and 8. In HEK 293 cells, expression of P2RX7L produces a protein isoform, P2X7L, that forms a heteromer with P2X7A. A haplotype defined by six single nucleotide polymorphisms (SNPs) (rs208307, rs208306, rs36144485, rs208308, rs208309, and rs373655596) promotes allele-specific alternative splicing, increasing mRNA levels of P2RX7L and another isoform, P2RX7E, which in addition has a truncated C-terminus. Skipping of exons 7 and 8 is predicted to delete critical amino acids in the ATP-binding site. P2X7L-transfected HEK 293 cells have phagocytic but not channel, pore, or membrane-blebbing function, and double-transfected P2X7L and P2X7A cells have reduced pore function. Heteromeric receptor complexes of P2X7A and P2X7L are predicted to have reduced numbers of ATP-binding sites, which potentially alters receptor function compared to homomeric P2X7A complexes.
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Affiliation(s)
- Kristen K Skarratt
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| | - Ben J Gu
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Michael D Lovelace
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| | - Carol J Milligan
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Leanne Stokes
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia.,School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Rachel Glover
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - James S Wiley
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Fuller
- Department of Medicine, Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Kingswood, NSW, Australia
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12
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Multiple Imaging Modalities for Cell-Cell Communication via Calcium Mobilizations in Corneal Epithelial Cells. Methods Mol Biol 2020; 2346:11-20. [PMID: 33159251 DOI: 10.1007/7651_2020_329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chemical indicators are used to study calcium signaling events in the context of live cell imaging. Fluo-3 AM, Fluo-4 AM, and Cal-520 AM are three commonly used fluorescent indicators derived from the calcium chelator BAPTA. Here we describe sample protocols that detail how these indicators are used in in vitro and ex vivo experiments to analyze the role of calcium mobilizations in cell-cell communication and coordinated cellular motility in the context of wound healing.
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13
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Calbiague VM, Vielma AH, Cadiz B, Paquet‐Durand F, Schmachtenberg O. Physiological assessment of high glucose neurotoxicity in mouse and rat retinal explants. J Comp Neurol 2019; 528:989-1002. [DOI: 10.1002/cne.24805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/09/2019] [Accepted: 10/20/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Víctor M. Calbiague
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
- Programa Doctorado en Ciencias, mención Neurociencias Universidad de Valparaíso Valparaíso Chile
| | - Alex H. Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| | - Bárbara Cadiz
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| | - Francois Paquet‐Durand
- Cell Death Mechanism Group Institute for Ophthalmic Research, University of Tübingen Tübingen Germany
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
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14
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García-Vega L, O'Shaughnessy EM, Jan A, Bartholomew C, Martin PE. Connexin 26 and 43 play a role in regulating proinflammatory events in the epidermis. J Cell Physiol 2019; 234:15594-15606. [PMID: 30710344 DOI: 10.1002/jcp.28206] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 01/15/2019] [Accepted: 01/16/2019] [Indexed: 01/24/2023]
Abstract
Dysregulation of Connexin (CX) expression and function is associated with a range of chronic inflammatory conditions including psoriasis and nonhealing wounds. To mimic a proinflammatory environment, HaCaT cells, a model human keratinocyte cell line, were challenged with 10 µg/ml peptidoglycan (PGN) isolated from Staphylococcus aureus for 15 min to 24 hr in the presence or absence of CX blockers and/or following CX26, CX43, PANX1 and TLR2 small interfering RNA (siRNA) knockdown (KD). Expression levels of IL-6, IL-8, CX26, CX43, PANX1, TLR2 and Ki67 were assessed by quantitative real-time polymerase chain reaction, western blot analysis and/or immunocytochemistry. Nuclear factor kappa β (NF-κβ) was blocked with BAY 11-7082, CX-channel function was determined by adenosine 5'-triphosphate (ATP) release assays. Enzyme-linked immunosorbent assay monitored IL6 release following PGN challenge in the presence or absence of siRNA or blockers of CX or purinergic signalling. Exposure to PGN induced IL-6, IL-8, CX26 and TLR2 gene expression but it did not influence CX43, PANX1 or Ki67 messenger RNA expression levels. CX43 protein levels were reduced following 24 hr PGN exposure. PGN-induced CX26 and IL-6 expression were also aborted by TLR2-KD and inhibition of NF-κβ. ATP and IL-6 release were stimulated following 15 min and 1-24 hr challenge with PGN, respectively. Release of both agents was inhibited by coincubation with CX-channel blockers, CX26-, CX43- and TLR2-KD. The IL-6 response was also reduced by purinergic blockers. CX-signalling plays a role in the innate immune response in the epidermis. PGN is detected by TLR2, which via NF-κβ, directly activates CX26 and IL-6 expression. CX43 and CX26 maintain proinflammatory signalling by permitting ATP release, however, PANX1 does not participate.
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Affiliation(s)
- Laura García-Vega
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UK
| | - Erin M O'Shaughnessy
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UK
| | - Afnan Jan
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UK
| | - Chris Bartholomew
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UK
| | - Patricia E Martin
- Department of Biological and Biomedical Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland, UK
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15
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Lee Y, Kim MT, Rhodes G, Sack K, Son SJ, Rich CB, Kolachalama VB, Gabel CV, Trinkaus-Randall V. Sustained Ca2+ mobilizations: A quantitative approach to predict their importance in cell-cell communication and wound healing. PLoS One 2019; 14:e0213422. [PMID: 31017899 PMCID: PMC6481807 DOI: 10.1371/journal.pone.0213422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/11/2019] [Indexed: 01/12/2023] Open
Abstract
Epithelial wound healing requires the coordination of cells to migrate as a unit over the basement membrane after injury. To understand the process of this coordinated movement, it is critical to study the dynamics of cell-cell communication. We developed a method to characterize the injury-induced sustained Ca2+ mobilizations that travel between cells for periods of time up to several hours. These events of communication are concentrated along the wound edge and are reduced in cells further away from the wound. Our goal was to delineate the role and contribution of these sustained mobilizations and using MATLAB analyses, we determined the probability of cell-cell communication events in both in vitro models and ex vivo organ culture models. We demonstrated that the injury response was complex and represented the activation of a number of receptors. In addition, we found that pannexin channels mediated the cell-cell communication and motility. Furthermore, the sustained Ca2+ mobilizations are associated with changes in cell morphology and motility during wound healing. The results demonstrate that both purinoreceptors and pannexins regulate the sustained Ca2+ mobilization necessary for cell-cell communication in wound healing.
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Affiliation(s)
- Yoonjoo Lee
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Min Tae Kim
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Garrett Rhodes
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Kelsey Sack
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Sung Jun Son
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Celeste B. Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Vijaya B. Kolachalama
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Christopher V. Gabel
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Vickery Trinkaus-Randall
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
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16
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Kneer K, Green MB, Meyer J, Rich CB, Minns MS, Trinkaus-Randall V. High fat diet induces pre-type 2 diabetes with regional changes in corneal sensory nerves and altered P2X7 expression and localization. Exp Eye Res 2018; 175:44-55. [PMID: 29883639 DOI: 10.1016/j.exer.2018.06.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/23/2018] [Accepted: 06/03/2018] [Indexed: 12/31/2022]
Abstract
Type 2 diabetes is one of the leading pathologies that increases the risk of improper wound healing. Obesity has become a major risk factor for this disease that is now considered to be the 4th highest cause of preventable blindness according to the World Health Organization. The cornea is the most densely innervated structure in the human body and senses even the slightest injury. In diabetes, decreased corneal sensitivity secondary to diabetic peripheral neuropathy can lead to increased corneal abrasion, ulceration, and even blindness. In this study, a diet induced obesity (DIO) mouse model of pre-Type 2 diabetes was used to characterize changes in sensory nerves and P2X7, a purinoreceptor, a pain receptor, and an ion channel that is expressed in a number of tissues. Since our previous studies demonstrated that P2X7 mRNA was significantly elevated in diabetic human corneas, we examined P2X7 expression and localization in the DIO murine model at various times after being fed a high fat diet. Fifteen weeks after onset of diet, we found that there was a significant decrease in the density of sub-basal nerves in the DIO mice that was associated with an increase in tortuosity and a decrease in diameter. In addition, P2X7 mRNA expression was significantly greater in the corneal epithelium of DIO mice, and the increase in transcript was enhanced in the central migrating and peripheral regions after injury. Interestingly, confocal microscopy and thresholding analysis revealed that there was a significant increase in P2X7 distal to the injury, which contrasted with a decrease in P2X7-expressing stromal sensory nerves. Therefore, we hypothesize that the P2X7 receptor acts to sense changes at the leading edge following an epithelial abrasion, and this fine-tuned regulation is lost during the onset of diabetes. Further understanding of the corneal changes that occur in diabetes can help us better monitor progression of diabetic complications, as well as develop new therapeutics for the treatment of diabetic corneal dysfunction.
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Affiliation(s)
- Krisandra Kneer
- Boston University School of Medicine, 80 E. Concord St. Boston, MA, 02118, USA.
| | - Michael B Green
- Boston University School of Medicine, 80 E. Concord St. Boston, MA, 02118, USA.
| | - Jenna Meyer
- Boston University School of Medicine, 80 E. Concord St. Boston, MA, 02118, USA.
| | - Celeste B Rich
- Boston University School of Medicine, 80 E. Concord St. Boston, MA, 02118, USA.
| | - Martin S Minns
- Boston University School of Medicine, 80 E. Concord St. Boston, MA, 02118, USA.
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17
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The Role of the P2X7 Receptor in Ocular Stresses: A Potential Therapeutic Target. Vision (Basel) 2017; 1:vision1020014. [PMID: 31740640 PMCID: PMC6835678 DOI: 10.3390/vision1020014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/10/2017] [Accepted: 05/14/2017] [Indexed: 01/30/2023] Open
Abstract
The P2X7 receptor is expressed in both anterior and posterior segments of the eyeball. In the ocular surface, the P2X7 receptor is activated in case of external aggressions: preservatives and surfactants induce the activation of P2X7 receptors, leading to either apoptosis, inflammation, or cell proliferation. In the retina, the key endogenous actors of age-related macular degeneration, diabetic retinopathy, and glaucoma act through P2X7 receptors’ activation and/or upregulation of P2X7 receptors’ expression. Different therapeutic strategies aimed at the P2X7 receptor exist. P2X7 receptor antagonists, such as divalent cations and Brilliant Blue G (BBG) could be used to target either the ocular surface or the retina, as long as polyunsaturated fatty acids may exert their effects through the disruption of plasma membrane lipid rafts or saffron that reduces the response evoked by P2X7 receptor stimulation. Treatments against P2X7 receptor activation are proposed by using either eye drops or food supplements.
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18
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Diabetic complications in the cornea. Vision Res 2017; 139:138-152. [PMID: 28404521 DOI: 10.1016/j.visres.2017.03.002] [Citation(s) in RCA: 148] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/31/2017] [Accepted: 03/31/2017] [Indexed: 12/15/2022]
Abstract
Diabetic corneal alterations, such as delayed epithelial wound healing, edema, recurrent erosions, neuropathy/loss of sensitivity, and tear film changes are frequent but underdiagnosed complications of both type 1 (insulin-dependent) and type 2 (non-insulin-dependent) diabetes mellitus. The disease affects corneal epithelium, corneal nerves, tear film, and to a lesser extent, endothelium, and also conjunctiva. These abnormalities may appear or become exacerbated following trauma, as well as various surgeries including retinal, cataract or refractive. The focus of the review is on mechanisms of diabetic corneal abnormalities, available animal, tissue and organ culture models, and emerging treatments. Changes of basement membrane structure and wound healing rates, the role of various proteinases, advanced glycation end products (AGEs), abnormal growth and motility factors (including opioid, epidermal, and hepatocyte growth factors) are analyzed. Experimental therapeutics under development, including topical naltrexone, insulin, inhibitors of aldose reductase, and AGEs, as well as emerging gene and cell therapies are discussed in detail.
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19
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Guzman-Aranguez A, Pérez de Lara MJ, Pintor J. Hyperosmotic stress induces ATP release and changes in P2X7 receptor levels in human corneal and conjunctival epithelial cells. Purinergic Signal 2017; 13:249-258. [PMID: 28176024 DOI: 10.1007/s11302-017-9556-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/25/2017] [Indexed: 12/31/2022] Open
Abstract
Tear hyperosmolarity is a key event in dry eye. In this work, we analyzed whether hyperosmolar challenge induces ATP release on the ocular surface. Moreover, as extracellular ATP can activate P2X7 receptor, the changes in P2X7 protein levels and its involvement in pathological process triggered by hypertonic treatment were also examined. High-performance liquid chromatography analysis revealed that ATP levels significantly increased in human corneal and conjunctival epithelial cells exposed to hyperosmotic challenge as well as in dry eye patients as compared to control subjects. A significant reduction in cell viability was detected after hyperosmolar treatment, indicating that the rise in ATP release was mainly due to cell lysis/death. Additionally, vesicular nucleotide transporter was identified in both cell lines and their protein expression was upregulated in hypertonic media. P2X7 receptor truncated form together with the full-length form was identified in both cell lines, and experiments using specific antagonist and agonist for P2X7 indicated that this receptor did not mediate cell death induced by hyperosmolar stress. In conclusion, hyperosmotic stress induces ATP release. Extracellular ATP can activate P2X7 receptor leading to cytotoxicity in many cells/tissues; however, this does not occur in human corneal and conjunctival epithelial cells. In these cells, the presence of P2X7 receptor truncated form together with the full-length form hinders a P2X7 apoptotic behavior on the ocular surface.
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Affiliation(s)
- Ana Guzman-Aranguez
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, C/Arcos de Jalón 118, 28037, Madrid, Spain.
| | - María J Pérez de Lara
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, C/Arcos de Jalón 118, 28037, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, C/Arcos de Jalón 118, 28037, Madrid, Spain
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20
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Minns MS, Trinkaus-Randall V. Purinergic Signaling in Corneal Wound Healing: A Tale of 2 Receptors. J Ocul Pharmacol Ther 2016; 32:498-503. [PMID: 27643999 DOI: 10.1089/jop.2016.0009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Nucleotide release and purinergic signaling make up the earliest response to corneal injury and are vital for proper wound healing. In this study, we review the importance of nucleotide release in the injury response and focus on the contribution of 2 receptors that mediate purinergic signaling, P2Y2 and P2X7. These receptors mediate the early response to injury and activate downstream signaling to promote cytoskeletal rearrangement and cell migration. The contribution of corneal nerves to the purinergic injury response is also discussed. Finally, we look at implications of altered purinergic signaling in diabetic wound healing and important targets for future research.
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Affiliation(s)
- Martin S Minns
- 1 Department of Biochemistry, Boston University School of Medicine , Boston, Massachusetts
| | - Vickery Trinkaus-Randall
- 1 Department of Biochemistry, Boston University School of Medicine , Boston, Massachusetts.,2 Department of Ophthalmology, Boston University School of Medicine , Boston, Massachusetts
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21
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Alvarez A, Lagos-Cabré R, Kong M, Cárdenas A, Burgos-Bravo F, Schneider P, Quest AFG, Leyton L. Integrin-mediated transactivation of P2X7R via hemichannel-dependent ATP release stimulates astrocyte migration. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:2175-88. [PMID: 27235833 DOI: 10.1016/j.bbamcr.2016.05.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/29/2016] [Accepted: 05/23/2016] [Indexed: 01/09/2023]
Abstract
Our previous reports indicate that ligand-induced αVβ3 integrin and Syndecan-4 engagement increases focal adhesion formation and migration of astrocytes. Additionally, ligated integrins trigger ATP release through unknown mechanisms, activating P2X7 receptors (P2X7R), and the uptake of Ca(2+) to promote cell adhesion. However, whether the activation of P2X7R and ATP release are required for astrocyte migration and whether αVβ3 integrin and Syndecan-4 receptors communicate with P2X7R via ATP remains unknown. Here, cells were stimulated with Thy-1, a reported αVβ3 integrin and Syndecan-4 ligand. Results obtained indicate that ATP was released by Thy-1 upon integrin engagement and required the participation of phosphatidylinositol-3-kinase (PI3K), phospholipase-C gamma (PLCγ) and inositol trisphosphate (IP3) receptors (IP3R). IP3R activation leads to increased intracellular Ca(2+), hemichannel (Connexin-43 and Pannexin-1) opening, and ATP release. Moreover, silencing of the P2X7R or addition of hemichannel blockers precluded Thy-1-induced astrocyte migration. Finally, Thy-1 lacking the integrin-binding site did not stimulate ATP release, whereas Thy-1 mutated in the Syndecan-4-binding domain increased ATP release, albeit to a lesser extent and with delayed kinetics compared to wild-type Thy-1. Thus, hemichannels activated downstream of an αVβ3 integrin-PI3K-PLCγ-IP3R pathway are responsible for Thy-1-induced, hemichannel-mediated and Syndecan-4-modulated ATP release that transactivates P2X7Rs to induce Ca(2+) entry. These findings uncover a hitherto unrecognized role for hemichannels in the regulation of astrocyte migration via P2X7R transactivation induced by integrin-mediated ATP release.
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Affiliation(s)
- Alvaro Alvarez
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile
| | - Raúl Lagos-Cabré
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile
| | - Milene Kong
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile
| | - Areli Cárdenas
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile
| | - Francesca Burgos-Bravo
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile
| | - Pascal Schneider
- Department of Biochemistry, University of Lausanne, 1066 Epalinges, Switzerland
| | - Andrew F G Quest
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Advanced Center for Chronic Diseases, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile
| | - Lisette Leyton
- Cellular Communication Laboratory, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Advanced Center for Chronic Diseases, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile; Biomedical Neuroscience Institute, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, 838-0453 Santiago, Chile.
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22
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Giblin JP, Comes N, Strauss O, Gasull X. Ion Channels in the Eye: Involvement in Ocular Pathologies. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2015; 104:157-231. [PMID: 27038375 DOI: 10.1016/bs.apcsb.2015.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The eye is the sensory organ of vision. There, the retina transforms photons into electrical signals that are sent to higher brain areas to produce visual sensations. In the light path to the retina, different types of cells and tissues are involved in maintaining the transparency of avascular structures like the cornea or lens, while others, like the retinal pigment epithelium, have a critical role in the maintenance of photoreceptor function by regenerating the visual pigment. Here, we have reviewed the roles of different ion channels expressed in ocular tissues (cornea, conjunctiva and neurons innervating the ocular surface, lens, retina, retinal pigment epithelium, and the inflow and outflow systems of the aqueous humor) that are involved in ocular disease pathophysiologies and those whose deletion or pharmacological modulation leads to specific diseases of the eye. These include pathologies such as retinitis pigmentosa, macular degeneration, achromatopsia, glaucoma, cataracts, dry eye, or keratoconjunctivitis among others. Several disease-associated ion channels are potential targets for pharmacological intervention or other therapeutic approaches, thus highlighting the importance of these channels in ocular physiology and pathophysiology.
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Affiliation(s)
- Jonathan P Giblin
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Nuria Comes
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | | | - Xavier Gasull
- Universitat de Barcelona, Barcelona, Spain; Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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Minns MS, Teicher G, Rich CB, Trinkaus-Randall V. Purinoreceptor P2X7 Regulation of Ca(2+) Mobilization and Cytoskeletal Rearrangement Is Required for Corneal Reepithelialization after Injury. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 186:285-96. [PMID: 26683661 DOI: 10.1016/j.ajpath.2015.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 10/05/2015] [Accepted: 10/16/2015] [Indexed: 01/17/2023]
Abstract
The process of wound healing involves a complex network of signaling pathways working to promote rapid cell migration and wound closure. Activation of purinergic receptors by secreted nucleotides plays a major role in calcium mobilization and the subsequent calcium-dependent signaling that is essential for proper healing. The role of the purinergic receptor P2X7 in wound healing is still relatively unknown. We demonstrate that P2X7 expression increases at the leading edge of corneal epithelium after injury in an organ culture model, and that this change occurs despite an overall decrease in P2X7 expression throughout the epithelium. Inhibition of P2X7 prevents this change in localization after injury and impairs wound healing. In cell culture, P2X7 inhibition attenuates the amplitude and duration of injury-induced calcium mobilization in cells at the leading edge. Immunofluorescence analysis of scratch-wounded cells reveals that P2X7 inhibition results in an overall decrease in the number of focal adhesions along with a concentration of focal adhesions at the wound margin. Live cell imaging of green fluorescent protein-labeled actin and talin shows that P2X7 inhibition alters actin cytoskeletal rearrangements and focal adhesion dynamics after injury. Together, these data demonstrate that P2X7 plays a critical role in mediating calcium signaling and coordinating cytoskeletal rearrangement at the leading edge, both of which processes are early signaling events necessary for proper epithelial wound healing.
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Affiliation(s)
- Martin S Minns
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts
| | - Gregory Teicher
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts
| | - Celeste B Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts
| | - Vickery Trinkaus-Randall
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts.
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Sanderson J, Dartt DA, Trinkaus-Randall V, Pintor J, Civan MM, Delamere NA, Fletcher EL, Salt TE, Grosche A, Mitchell CH. Purines in the eye: recent evidence for the physiological and pathological role of purines in the RPE, retinal neurons, astrocytes, Müller cells, lens, trabecular meshwork, cornea and lacrimal gland. Exp Eye Res 2014; 127:270-9. [PMID: 25151301 DOI: 10.1016/j.exer.2014.08.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/24/2014] [Accepted: 08/12/2014] [Indexed: 12/21/2022]
Abstract
This review highlights recent findings that describ how purines modulate the physiological and pathophysiological responses of ocular tissues. For example, in lacrimal glands the cross-talk between P2X7 receptors and both M3 muscarinic receptors and α1D-adrenergic receptors can influence tear secretion. In the cornea, purines lead to post-translational modification of EGFR and structural proteins that participate in wound repair in the epithelium and influence the expression of matrix proteins in the stroma. Purines act at receptors on both the trabecular meshwork and ciliary epithelium to modulate intraocular pressure (IOP); ATP-release pathways of inflow and outflow cells differ, possibly permitting differential modulation of adenosine delivery. Modulators of trabecular meshwork cell ATP release include cell volume, stretch, extracellular Ca(2+) concentration, oxidation state, actin remodeling and possibly endogenous cardiotonic steroids. In the lens, osmotic stress leads to ATP release following TRPV4 activation upstream of hemichannel opening. In the anterior eye, diadenosine polyphosphates such as Ap4A act at P2 receptors to modulate the rate and composition of tear secretion, impact corneal wound healing and lower IOP. The Gq11-coupled P2Y1-receptor contributes to volume control in Müller cells and thus the retina. P2X receptors are expressed in neurons in the inner and outer retina and contribute to visual processing as well as the demise of retinal ganglion cells. In RPE cells, the balance between extracellular ATP and adenosine may modulate lysosomal pH and the rate of lipofuscin formation. In optic nerve head astrocytes, mechanosensitive ATP release via pannexin hemichannels, coupled with stretch-dependent upregulation of pannexins, provides a mechanism for ATP signaling in chronic glaucoma. With so many receptors linked to divergent functions throughout the eye, ensuring the transmitters remain local and stimulation is restricted to the intended target may be a key issue in understanding how physiological signaling becomes pathological in ocular disease.
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Affiliation(s)
| | - Darlene A Dartt
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Vickery Trinkaus-Randall
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA; Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
| | - Jesus Pintor
- Department of Biochemistry, Faculty of Optometry, Universidad Complutense de Madrid, Madrid, Spain
| | - Mortimer M Civan
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Nicholas A Delamere
- Department of Physiology, University of Arizona, Tucson, AZ, USA; Department of Ophthalmology and Vision Science, University of Arizona, Tucson, AZ, USA
| | - Erica L Fletcher
- Department of Anatomy and of Neuroscience, University of Melbourne, Victoria, Australia
| | - Thomas E Salt
- Department of Visual Neuroscience, UCL Institute of Ophthalmology, London, UK
| | - Antje Grosche
- Institute of Human Genetics, Franz-Josef-Strauß-Allee, Regensburg, Germany
| | - Claire H Mitchell
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA; Department of Anatomy and Cell Biology, University of Pennsylvania, Philadelphia, PA, USA.
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25
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Purinergic receptors in ocular inflammation. Mediators Inflamm 2014; 2014:320906. [PMID: 25132732 PMCID: PMC4123590 DOI: 10.1155/2014/320906] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 06/17/2014] [Indexed: 01/01/2023] Open
Abstract
Inflammation is a complex process that implies the interaction between cells and molecular mediators, which, when not properly “tuned,” can lead to disease. When inflammation affects the eye, it can produce severe disorders affecting the superficial and internal parts of the visual organ. The nucleoside adenosine and nucleotides including adenine mononucleotides like ADP and ATP and dinucleotides such as P1,P4-diadenosine tetraphosphate (Ap4A), and P1,P5-diadenosine pentaphosphate (Ap5A) are present in different ocular locations and therefore they may contribute/modulate inflammatory processes. Adenosine receptors, in particular A2A adenosine receptors, present anti-inflammatory action in acute and chronic retinal inflammation. Regarding the A3 receptor, selective agonists like N6-(3-iodobenzyl)-5′-N-methylcarboxamidoadenosine (CF101) have been used for the treatment of inflammatory ophthalmic diseases such as dry eye and uveoretinitis. Sideways, diverse stimuli (sensory stimulation, large intraocular pressure increases) can produce a release of ATP from ocular sensory innervation or after injury to ocular tissues. Then, ATP will activate purinergic P2 receptors present in sensory nerve endings, the iris, the ciliary body, or other tissues surrounding the anterior chamber of the eye to produce uveitis/endophthalmitis. In summary, adenosine and nucleotides can activate receptors in ocular structures susceptible to suffer from inflammatory processes. This involvement suggests the possible use of purinergic agonists and antagonists as therapeutic targets for ocular inflammation.
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Lee A, Derricks K, Minns M, Ji S, Chi C, Nugent MA, Trinkaus-Randall V. Hypoxia-induced changes in Ca(2+) mobilization and protein phosphorylation implicated in impaired wound healing. Am J Physiol Cell Physiol 2014; 306:C972-85. [PMID: 24671101 DOI: 10.1152/ajpcell.00110.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The process of wound healing must be tightly regulated to achieve successful restoration of injured tissue. Previously, we demonstrated that when corneal epithelium is injured, nucleotides and neuronal factors are released to the extracellular milieu, generating a Ca(2+) wave from the origin of the wound to neighboring cells. In the present study we sought to determine how the communication between epithelial cells in the presence or absence of neuronal wound media is affected by hypoxia. A signal-sorting algorithm was developed to determine the dynamics of Ca(2+) signaling between neuronal and epithelial cells. The cross talk between activated corneal epithelial cells in response to neuronal wound media demonstrated that injury-induced Ca(2+) dynamic patterns were altered in response to decreased O2 levels. These alterations were associated with an overall decrease in ATP and changes in purinergic receptor-mediated Ca(2+) mobilization and localization of N-methyl-d-aspartate receptors. In addition, we used the cornea in an organ culture wound model to examine how hypoxia impedes reepithelialization after injury. There was a change in the recruitment of paxillin to the cell membrane and deposition of fibronectin along the basal lamina, both factors in cell migration. Our results provide evidence that complex Ca(2+)-mediated signaling occurs between sensory neurons and epithelial cells after injury and is critical to wound healing. Information revealed by these studies will contribute to an enhanced understanding of wound repair under compromised conditions and provide insight into ways to effectively stimulate proper epithelial repair.
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Affiliation(s)
- Albert Lee
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and
| | - Kelsey Derricks
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and
| | - Martin Minns
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and
| | - Sophina Ji
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
| | - Cheryl Chi
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
| | - Matthew A Nugent
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
| | - Vickery Trinkaus-Randall
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts; and Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts
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27
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Rokic MB, Stojilkovic SS. Two open states of P2X receptor channels. Front Cell Neurosci 2013; 7:215. [PMID: 24312007 PMCID: PMC3834609 DOI: 10.3389/fncel.2013.00215] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 10/29/2013] [Indexed: 11/16/2022] Open
Abstract
The occupancy of the orthosteric ligand binding sites of P2X receptor (P2XR) channels causes the rapid opening of a small cation-permeable pore, followed by a gradual dilation that renders the pore permeable to large organic cations. Electrophysiologically, this phenomenon was shown using whole-cell current recording on P2X2R-, P2X2/X5R-, P2X4R- and P2X7R-expressing cells that were bathed in N-methyl-D-glucamine (NMDG+)-containing buffers in the presence and/or absence of small monovalent and divalent cations. The pore dilation of P2X4R and P2X7R caused a secondary current growth, whereas that of P2X2R showed a sustained kinetic coupling of dilation and desensitization, leading to receptor channel closure. The pore size of the P2X7R open and dilated states was estimated to be approximately 0.85 nm and greater than 1 nm, respectively. The P2XR pore dilation was also observed in intact cells by measurement of fluorescent dye uptake/release, application of polyethylene glycols of different sizes, and atomic force microscopy. However, pore dilation was not observed at the single channel level. Structural data describing the dilated state are not available, and the relevance of orthosteric and allosteric ligand interactions to pore dilation was not studied.
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Affiliation(s)
- Milos B Rokic
- Section on Cellular Signaling, Program in Developmental Neuroscience, The Eunice Kennedy Shiver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
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28
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Chi C, Trinkaus-Randall V. New insights in wound response and repair of epithelium. J Cell Physiol 2013; 228:925-9. [PMID: 23129239 DOI: 10.1002/jcp.24268] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 10/18/2012] [Indexed: 01/26/2023]
Abstract
Epithelial wounds usually heal relatively quickly, but repair may be impaired by environmental stressors, such as hypoxic or diabetic states, rendering patients vulnerable to a number of corneal pathologies. Though this response appears simple, at first, years of research have uncovered the complicated biochemical pathways coordinating the wound healing response. Here, we investigate signaling cascades and individual proteins involved in the corneal epithelium's self-repair. We will explore how an epithelial cell migrates across the wound bed and attaches itself to its new post-injury surroundings, including its neighboring cells and the basement membrane, through focal adhesions and hemidesmosomes. We will also discuss how the cell coordinates this motion physiologically, through calcium signaling and protein phosphorylation, focusing on the communication through purinergic, glutamatergic, and growth factor receptors. Many of these aspects reflect and can be extended to similar epithelial surfaces, and can be used to facilitate wound healing in patients with various underlying pathologies. The collective library of laboratory and clinical research done around the world has demonstrated how important precise regulation of these processes is in order for the injured corneal epithelium to properly heal.
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Affiliation(s)
- Cheryl Chi
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, USA
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29
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Killeen ME, Ferris L, Kupetsky EA, Falo L, Mathers AR. Signaling through purinergic receptors for ATP induces human cutaneous innate and adaptive Th17 responses: implications in the pathogenesis of psoriasis. THE JOURNAL OF IMMUNOLOGY 2013; 190:4324-36. [PMID: 23479230 DOI: 10.4049/jimmunol.1202045] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Human cutaneous dendritic cells (DCs) have the ability to prime and bias Th17 lymphocytes. However, the factors that stimulate cutaneous DCs to induce Th17 responses are not well known. Alarmins, such as ATP, likely play a pivotal role in the induction and maintenance of cutaneous immune responses by stimulating DC maturation, chemotaxis, and secretion of IL-1β and IL-6, Th17-biasing cytokines. In this study, using a well-established human skin model, we have demonstrated that signaling purinergic receptors, predominantly the P2X7 receptor (P2X7R), via an ATP analog initiate innate proinflammatory inflammation, DC17 differentiation, and the subsequent induction of Th17-biased immunity. Moreover, our results suggest a potential role for P2X7R signaling in the initiation of psoriasis pathogenesis, a Th17-dependent autoimmune disease. In support of this, we observed the increased presence of P2X7R in nonlesional and lesional psoriatic skin compared with normal healthy tissues. Interestingly, there was also a P2X7R variant that was highly expressed in lesional psoriatic skin compared with nonlesional psoriatic and normal healthy skin. Furthermore, we demonstrated that psoriatic responses could be initiated via P2X7R signaling in nonlesional skin following treatment with a P2X7R agonist. Mechanistic studies revealed a P2X7R-dependent mir-21 angiogenesis pathway that leads to the expression of vascular endothelial growth factor and IL-6 and that may be involved in the development of psoriatic lesions. In conclusion, we have established that purinergic signaling in the skin induces innate inflammation, leading to the differentiation of human Th17 responses, which have implications in the pathogenesis and potential treatment of psoriasis.
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Affiliation(s)
- Meaghan E Killeen
- Department of Dermatology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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30
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Ghazi K, Deng-Pichon U, Warnet JM, Rat P. Hyaluronan fragments improve wound healing on in vitro cutaneous model through P2X7 purinoreceptor basal activation: role of molecular weight. PLoS One 2012; 7:e48351. [PMID: 23173033 PMCID: PMC3500239 DOI: 10.1371/journal.pone.0048351] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 09/24/2012] [Indexed: 01/19/2023] Open
Abstract
Background hyaluronan biopolymer is used in dermatology but the underlying mechanism and the impact of its molecular weight have not yet been investigated in skin wound healing. The aim of our work was to study the role of HA molecular weight in the proliferative phase of wound healing and to understand how this physiological biopolymer acts to promote wound healing on a human keratinocyte in vitro model. Methodology and Findings wound healing closure was evaluated using scratch test assay, cell proliferation by counting cell with haemocytometer, expression of CD44 and ZO-1 (protein present in tight junctions specific of epithelia) using flow cytometry, and P2X7 receptor activation on living using a cytoflurometric method. Our study showed that medium hyaluronan fragment (MMW-HA, between 100 and 300 kDa) induced a significant increase in wound closure, increased ZO-1 protein expression and induced a slight activation of P2X7 receptor, contrary to high (between 1000 and 1400 kDa) and low (between 5 and 20 kDa) molecular hyaluronan fragments that had no healing effects. Basal activation of P2X7 receptor is already known to stimulate cell proliferation and this activation in our model plays a pivotal role in MMW-HA-induced wound healing. Indeed, we showed that use of BBG, a specific inhibitor of P2X7 receptor, blocked completely the beneficial effects of MMW-HA on wound healing. Conclusion taken together, our results showed for the first time the relationship between P2X7 receptor and hyaluronan in wound healing, and that topical use of MMW-HA (fragment between 100 and 300 kDa) could represent a new therapeutic strategy to promote healing.
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Affiliation(s)
- Kamelia Ghazi
- Chimie-Toxicologie Analytique et Cellulaire (EA 4463), Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Uriell Deng-Pichon
- Chimie-Toxicologie Analytique et Cellulaire (EA 4463), Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Jean-Michel Warnet
- Chimie-Toxicologie Analytique et Cellulaire (EA 4463), Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Patrice Rat
- Chimie-Toxicologie Analytique et Cellulaire (EA 4463), Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
- * E-mail:
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31
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Oswald DJ, Lee A, Trinidad M, Chi C, Ren R, Rich CB, Trinkaus-Randall V. Communication between corneal epithelial cells and trigeminal neurons is facilitated by purinergic (P2) and glutamatergic receptors. PLoS One 2012; 7:e44574. [PMID: 22970252 PMCID: PMC3436752 DOI: 10.1371/journal.pone.0044574] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 08/09/2012] [Indexed: 01/15/2023] Open
Abstract
Previously, we demonstrated that nucleotides released upon mechanical injury to corneal epithelium activate purinergic (P2) receptors resulting in mobilization of a Ca2+ wave. However, the tissue is extensively innervated and communication between epithelium and neurons is critical and not well understood. Therefore, we developed a co-culture of primary trigeminal neurons and human corneal limbal epithelial cells. We demonstrated that trigeminal neurons expressed a repertoire of P2Yand P2X receptor transcripts and responded to P2 agonists in a concentration-dependent manner. Mechanical injuries to epithelia in the co-cultures elicited a Ca2+ wave that mobilized to neurons and was attenuated by Apyrase, an ectonucleotidase. To elucidate the role of factors released from each cell type, epithelial and neuronal cells were cultured, injured, and the wound media from one cell type was collected and added to the other cell type. Epithelial wound media generated a rapid Ca2+ mobilization in neuronal cells that was abrogated in the presence of Apyrase, while neuronal wound media elicited a complex response in epithelial cells. The rapid Ca2+ mobilization was detected, which was abrogated with Apyrase, but it was followed by Ca2+ waves that occurred in cell clusters. When neuronal wound media was preincubated with a cocktail of N-methyl-D-aspartate (NMDA) receptor inhibitors, the secondary response in epithelia was diminished. Glutamate was detected in the neuronal wound media and epithelial expression of NMDA receptor subunit transcripts was demonstrated. Our results indicate that corneal epithelia and neurons communicate via purinergic and NMDA receptors that mediate the wound response in a highly orchestrated manner.
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Affiliation(s)
- Duane J Oswald
- Departments of Biochemistry and Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
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